A Pyridinium Ylide-alkylation Strategy for the Structural Diversification of N-Carbamoyl Pyridinium Salts

A pyridinium-ylide alkylation strategy has been developed for accessing N,N-disubstituted carbamoyl pyridinium salts that possess multiple nucleophilic sites. The method was shown to be tolerant towards an array of different pyridinium scaffolds and common electrophiles; enabling access to structurally diverse pyridinium salts. The potential versatility of the approach was demonstrated through the synthesis of chemically complex, heterotrifunctional pyridinium salts containing a pyridinium warhead, a click chemistry handle, and a third, high-value, payload.